1. Field of the Invention
The present invention relates to an arrangement for suppressing interference waves and harmonic waves in traveling wave tubes with a short circuiting slide in the output wave guide.
2. Description of the Prior Art
German Patent No. 2,132,092 discloses a high frequency line in the form of a wave guide or coaxial conductor which has at least one attenuated auxiliary line coupled thereto, the auxiliary line being tuned to the frequency of the spurious oscillations by way of a number of periodically consecutive coupling openings, as a filter for undesired spurious oscillations, particularly harmonic waves. The auxiliary line is dimensioned such that the fundamental wave which is to be transmitted through the main line lies outside of the transmission range of the auxiliary line and the spurious oscillations couple into the auxiliary line from the main line. The auxiliary line is provided with a delay structure which is housed in the wall of the main line, to which attenuation bodies are brought into close proximity so as to displace the transmission range of the auxiliary line to longer waves.
Harmonic waves and higher interfering waves cause ripple in the frequency response of the amplification curve and the group delay of traveling wave amplifiers and, thus, such waves must be reduced to a small level. This occurs by means of a harmonic wave filter in the form of an attenuated delay line which greatly reduces the harmonic waves, but which insignificantly reduces the fundamental wave.